Investigation of the effect of simulated lens yellowing, transparency loss and refractive error on in vivo resonance Raman spectroscopy

To separately investigate the impact of simulated age-related lens yellowing, transparency loss and refractive error on measurements of macular pigment (MP) using resonance Raman spectroscopy.

Family caregiver views on patient-centred care at the end of life

Aim: The purpose of this study was to evaluate the patient-centredness of community palliative care from the perspective of family members who were responsible for the care of a terminally ill family member. Method: A survey questionnaire was mailed to families of a deceased family member who had been designated as palliative and had received formal home care services in the central west region of the Province of Ontario, Canada. Respondents reported on service use in the last four weeks of life; the Client-Centred Care Questionnaire (CCCQ) was used to evaluate the extent to which care was patient-centred. The accessibility instrument was used to assess respondent perception of access to care. Descriptive and inferential statistics were used for data analyses. Results: Of the 243 potential participants, 111 (46.0%) family caregivers completed the survey questionnaire. On average, respondents reported that they used five different services during the last four weeks of the care recipient's life. When asked about programme accessibility, care was also perceived as largely accessible and responsive to patients' changing needs (M=4.3 (SD=1.04)]. Most respondents also reported that they knew what service provider to contact if they experienced any problems concerning the care of their family member. However, this service provider was not consistent among respondents. Most respondents were relatively positive about the patient-centred care they received. There were however considerable differences between some items on the CCCQ. Respondents tended to provide more negative ratings concerning practical arrangement and the organization of care: who was coming, how often and when. They also rated more negatively the observation that service providers were quick to say something was possible when it was not the case. Bivariate analyses found no significant differences in CCCQ or accessibility domain scores by caregiver age, care recipient age, income, education and caregiver sex. Conclusions: Patient-centred care represents a service attribute that should be recognized as an important outcome to assess the quality of service delivery. This study demonstrates how this attribute can be evaluated in the provision of care. © 2011 The Authors. Scandinavian Journal of Caring Sciences © 2011 Nordic College of Caring Science.

Collaborative practice:a strategy to improve the relevance of health services research.

Health services research has emerged as a tool for decision makers to make services more effective and efficient. While its value as a basis for decision making is well established, the incorporation of such evidence into decision making remains inconsistent. To this end, strengthening collaborative relationships between researchers and healthcare decision makers has been identified as a significant strategy for putting research evidence into practice.

Morphometric analysis of corneal endothelial giant cells in normal and traumatized corneas

Corneal endothelial cells from normal and traumatized human, primate, cat and rabbit eyes were studied by specular microscopy. Morphometric analysis was performed on micrographs of corneal endothelium using a semi-automated image analysis system. The results showed that under normal conditions the corneal endothelium of all four species exhibit major morphological similarities (mean cell areas: human 317 +/- 32 microns 2, primate 246 +/- 22 microns2, cat 357 +/- 25 microns 2, rabbit 308 +/- 35 microns 2). The normal corneal endothelium in man was found to be more polymegethous than that of the other species. Trauma to cat, primate and human corneas resulted in a long-term reduction in endothelial cell density and enhanced polymegethism. In contrast, the reparative response of the rabbit ensured the reformation of an essentially normal monolayer following injury. Endothelial giant cells were a normal inclusion in the rabbit corneal endothelium but were only significant in cat, primate and man following trauma. The presence of corneal endothelial giant cells in amitotic corneas may therefore represent a compensatory response in the absence of mitotic potential.

Defining Target Volumes for Stereotactic Ablative Radiotherapy of Early-stage Lung Tumours:A Comparison of Three-dimensional F-fluorodeoxyglucose Positron Emission Tomography and Four-dimensional Computed Tomography

Aims: High local control rates are achieved in stage I lung cancer using stereotactic ablative radiotherapy. Target delineation is commonly based on four-dimensional computed tomography (CT) scans. Target volumes defined by positron emission tomography/computed tomography (PET/CT) are compared with those defined by four-dimensional CT and conventional ('three-dimensional') F-fluorodeoxyglucose (F-FDG) PET/CT. Materials and methods: For 16 stage I non-small cell lung cancer tumours, six approaches for deriving PET target volumes were evaluated: manual contouring, standardised uptake value (SUV) absolute threshold of 2.5, 35% of maximum SUV (35%SUV), 41% of SUV (41%SUV) and two different source to background ratio techniques (SBR-1 and SBR-2). PET-derived target volumes were compared with the internal target volume (ITV) from the modified maximum intensity projection (MIP ITV). Volumetric and positional correlation was assessed using the Dice similarity coefficient (DSC). Results: PET-based target volumes did not correspond to four-dimensional CT-based target volumes. The mean DSC relative to MIP ITV were: PET manual = 0.64, SUV2.5 = 0.64, 35%SUV = 0.63, 41%SUV = 0.57. SBR-1 = 0.52, SBR-2 = 0.49. PET-based target volumes were smaller than corresponding MIP ITVs. Conclusions: Conventional three-dimensional F-FDG PET-derived target volumes for lung stereotactic ablative radiotherapy did not correspond well with those derived from four-dimensional CT, including those in routine clinical use (MIP ITV). Caution is required in using three-dimensional PET for motion encompassing target volume delineation. © 2012 The Royal College of Radiologists.

Management of hyperkalaemia

Hyperkalaemia, an elevated extracellular fluid potassium concentration, is a common electrolyte disorder and is present in 1-10% of hospitalised patients. Elevated serum potassium concentrations are usually asymptomatic but may be associated with electrocardiogram (ECG) changes. Hyperkalaemia occasionally leads to life-threatening cardiac arrhythmias. Prompt recognition of this disorder, patient risk management and administration of appropriate treatment can prevent serious cardiac complications of hyperkalaemia. Further assessment of the underlying basis for hyperkalaemia usually reveals a problem with renal potassium excretion (rather than transcellular shift of potassium or excess potassium intake). Reduced potassium excretion is typically associated with decreased potassium secretion in the aldosterone-sensitive distal nephron of the kidney. Common causes for hyperkalaemia include kidney failure, limited delivery of sodium and water to the distal nephron and drugs that inhibit the renin-angiotensin-aldosterone system. Treatment of life-threatening hyperkalaemia (particularly those patients with ECG changes) involves administration of intravenous calcium salts to stabilise the resting cardiac membrane potential. The potassium concentration can be lowered by administration of intravenous insulin combined with an infusion of glucose to stimulate intracellular uptake of potassium. Nebulised β-2 adrenoceptor agonists can augment the effects of intravenous insulin and glucose pending more definitive management of the recurrent hyperkalaemia risk. Additional management steps include stopping further potassium intake and careful review of prescribed drugs that may be adversely affecting potassium homeostasis. Changes to prescribing systems and an agreed institutional protocol for management of hyperkalaemia can improve patient safety for this frequently encountered electrolyte disorder.

Defining target volumes for stereotactic ablative radiotherapy of early-stage lung tumours: a comparison of three-dimensional 18F-fluorodeoxyglucose positron emission tomography and four-dimensional computed tomography.:PETCT versus 4DCT for SABR in Early Stage NSCLC

AIMS: High local control rates are achieved in stage I lung cancer using
stereotactic ablative radiotherapy. Target delineation is commonly based on
four-dimensional computed tomography (CT) scans. Target volumes defined by
positron emission tomography/computed tomography (PET/CT) are compared with those defined by four-dimensional CT and conventional ('three-dimensional')
(18)F-fluorodeoxyglucose ((18)F-FDG) PET/CT.

MATERIALS AND METHODS: For 16 stage I non-small cell lung cancer tumours, six
approaches for deriving PET target volumes were evaluated: manual contouring,
standardised uptake value (SUV) absolute threshold of 2.5, 35% of maximum SUV
(35%SUV(MAX)), 41% of SUV(MAX) (41%SUV(MAX)) and two different source to
background ratio techniques (SBR-1 and SBR-2). PET-derived target volumes were compared with the internal target volume (ITV) from the modified maximum
intensity projection (MIP(MOD) ITV). Volumetric and positional correlation was
assessed using the Dice similarity coefficient (DSC).

RESULTS: PET-based target volumes did not correspond to four-dimensional CT-based target volumes. The mean DSC relative to MIP(MOD) ITV were: PET manual = 0.64, SUV2.5 = 0.64, 35%SUV(MAX) = 0.63, 41%SUV(MAX) = 0.57. SBR-1 = 0.52, SBR-2 =0.49. PET-based target volumes were smaller than corresponding MIP ITVs.

CONCLUSIONS: Conventional three-dimensional (18)F-FDG PET-derived target volumes for lung stereotactic ablative radiotherapy did not correspond well with those derived from four-dimensional CT, including those in routine clinical use
(MIP(MOD) ITV). Caution is required in using three-dimensional PET for motion
encompassing target volume delineation.

Evidence underlying the clinical management of diabetic macular oedema

Diabetic retinopathy (DR) is the leading cause of visual loss in the developed world in those of working age, and its prevalence is predicted to double by 2025. The management of diabetic retinopathy has traditionally relied on screening, on laser treatment delivered by ophthalmologists, and on optimising blood glucose and blood pressure. Recent evidence suggests that the role of systemic factors is more complex than originally thought, and that drugs such as ACE inhibitors, fibrates and glitazones may all influence the course of diabetic macular oedema. Antagonism of vascular endothelial growth factor offers a new therapeutic avenue that may transform the management of diabetic macular oedema. Several other therapeutic options are under investigation and development, including aminoguanidine, sorbinol, ruboxistaurin and autologous stem cell transfusion. © Royal College of Physicians, 2013.